Method for producing slide fastener elements



' Jain. 9, 1945. WINTEIRH'ALTER 2,366,948

METHOD FOR PRODUCING SLIDE FASTENER ELEMENTS Filed Feb. 17, 1942 M 2 Sheets-Sheet 1 h Jail 9, 1945. wmf R LT I 2,366,948

METHOD FOR PRODUCING SLIDE FASTENER ELEMENTS Filed Feb. 17, 1942 2 Sheets-Sheet 2 InvezzZm- Z'ZZI/rZw ZUmZar%aZZezr dizzy.

Patented Jan. 9, .1945

- UNITED STATES METHGD FOR rnonucino SLIDE FASTENER ELEMENTS Martin Winterhalter', Morcote, .near Lugano,

Switierla'nd Application February 17',- 1942, SerialNo 43 Ll99 In Switzerland, November 11 1941 9 Claims.

This invention relates to a method for producing slide fastener elements of the type comprising an interlocking head portion at one end and two tape gripping jaws at the other end for attaching the element to the edge of a tape.

For producing fastener elements of this type it is known, for example, to punch them in successive end to end relation out of a strip of sheet material, by providing V-shaped diverging jaws. At the free ends of these jaws there are pro.- vided inwardly directed projections. For attaching these elements to a tape they are placed astride the reinforced edge of the tape and then.

the V-shaped jaws are squeezed together so that the projections at the end of the jaws are brought in clamping relation with the tape at the rear of the reinforced edge thereof. Owing to the V-shaped diverging jaws of the elements, a relatively high percentage of waste of strip material is obtained with this method of punching out the elements since the material cut out between the diverging jaws and between the outer edges of the jaws and the strip edges is lost.

In order to save strip material, it has already been proposed to' punch the elements from the strip with jaws extending longitudinally of the strip instead of diverging jaws. In this case the outer edges of the jaws can be formed by the edges of the strip of sheet materialand the'disi-i tance between these longitudinally extending jaws is smaller so that less material is wasted when punching out such elements from the strip. But for attaching such elements to the edge of the tape, the jaws have to be spread apartv before the reinforced edge of the tape can be introduced between them and afterwards the jaws are.

squeezed again into clamping relation with the tape. The repeated bending operation to which these jaws are subjected owing to being spread open and successively squeezed together again, results in weakening of the material of the jaws at the place where they are subjected'to deformation, and finished fasteners made with such elements are not very resistant against. a traction effort tending to pull the elements oftthe tape,

because the laws yield at the weakened place and fall off the tape.

Itis an object of the present invention to provide an improved method for producingfastener elements of the type referred to and to stamp the fastener elements from astrip of sheet material with a minimum waste of strip material. According to the invention the fastener elements are successively punched out from a strip of sheet I u and two tape gripping jaws formed each of a material with the end portions of successive elements in overlapping relation, so that a part only of the material situated between the two jaws, is wasted, and that a greater number of fastener elements can be punched out from a given length of strip than when the successive elements are cut out in end to end relation.

According to a preferred embodiment of the invention the "ends of the tape gripping jaws are formed without inwardly directed projections destined to be squeezed into clamping engagement with the tape, but the jaws are provided with end portions of relatively weak cross section, so that after placing the elements astride the edge of the tape, the end portions can be bent inwardly and clamped on the tape without requiring any squeezing or bending of the inner jaw portions. In this case no V-shaped diverging jaws are required and no spreading apart of the jaws is necessary, but the outer edges of the jaws can be formed by the longitudinal edges of the strip of material from which the elements are cutout,

The accompanying drawings show various examples pi fastener elements-made in accordance 2 with the present invention; anda preferred form of 'embpgiment of a punching. apparatus for carrying out the method according to the invention Fig. 1 is -'a plan view of a finished. fastener element produced according to my improved method,

Fig. 2 is a section along the line. II -'-.-,II. of Fig. 1. Fig. '3 is a plan view and ifigg a longitudinal section'of, a strip of materigL-showingdiagrammatically the manner of producing the fastener elements.

Fig.5 is a plan view of thelower or die carryfastener elements are cut out in reversed position with respect to that-,of=Fig. 3. Fig. 10 shows a further-example of manner of producing fastener elements. in accordance with the present invention.

The fastener element represented in Figs. and 2 comprises an interlocking head portion I jaw portion 2 joining the head portion and having a relatively stronger cross section, and an-end portion 3 of relatively weaker cross section. The head portion 1 is provided with the usual recess 4 in one face and projection 5 in the other face. An opening 6 is provided between the two jaw portions 2 to receive the reinforced edge of a band-shaped carrier or tape 8. The inner edge of the jaws following the edge of the opening 6 is provided with a shoulder 1 so that the end portions 3 are of less width and have a weaker cross section than the jaw portions 2. These end portions 3 are adapted to be bent inwardly as shown in dash and dot lines in Fig. 1, for attaching the element to the edge of the tape 8.

Figs. 3 and 4 diagrammatically represent the manner of producing the described fastener element. A sheet metal strip 9 having'a width corresponding to the width of the finished fastener element is fed in a step by step motion in the direction of the arrow between upper and lower parts of a punching tool. This tool comprises a perforating punch 10 which, after each feeding step of the strip 9, cuts a hole II, H, II" into the strip, this hole having the shape of the opening 6 between the jaw portions 2 of the element. A die punch 12 cooperates with a die l3 disposed on the other side of the strip and produces an impression into the strip after each feeding step-of the strip to form a socket 4 and corresponding projection 5. This impression is formed between two successive holes II and II' which have been cut out after previous feeding steps of the strip. A further punch I4 is provided with a cutting edge the shape of which corresponds to the dash and dot line l5 in Fig. 3 extending at the end of the opening II from opposed sides thereof to both edges of the strip 9. After each feeding step of the strip, a finished fastener element is severed from the end of the strip along the line l5 by means of the punch l4.

The line of separation l5 has such a shape that inside of this line the head portion l of the severed element is formed, while outside of this line the end portions 3 of the following element are formed which will be severed from the strip after the next feeding step.

Owing to this overlapping relation between the head of one fastener element and the jaws of the next following element, the waste of strip material produced when cutting out the element, is reduced to a minimum, only the material forming the openings H, I I, ll" being lost, and this opening only extends through substantially one half of the length of the gripping jaws. The distance between successive holes II, H, ii, and the distance between the successive interlocking sockets 4 is less than the length of a finished fastener element, because successive elements have overlapping portions, namely the jaw portions 3 and head portion l, and the feed motion corresponding to each feed step is also smaller than the length of a fastener element.

The step by step feeding motion of the strip 9 can be produced by any convenient means, for

instance by advancing the strip by means of two intermittently rotating feeding rollers ll (Figs. 5

and 6) towards a fixed abutment l6. As soon as the end of the strip arrives at the abutment and the further advancing motion ceases, the three punches l0, l2 and M are simultaneously pressed downwardly, and in moving downwards the punch l4 severs a finished fastener element from the strip 9 while simultaneously it cuts out the end portions 3 of a further element which will be severed from the strip at the next following stroke of the punch l4. The punch 12 produces the socket 4 and projection 5 of the head of this further element, while the punch lllcuts a hole II" producing the jaw portions 2 in a more backwardly situated part of the strip 9.

In the position of the strip 9 shown in Figs. 3 and 4 a finished fastener element represented in dash and dot lines has just been severed from the strip and simultaneously the jaw end portions 3 of a further element have been formed. The punch I! has formed the socket 4 and projection 5 between the holes H and II and the punch H! has cut the hole H". The punches are now retracted and the strip 9 is advanced until the jaw ends 3 of the partly formed, next following fastener element arrive against the abutment surface l9 and then the three punches l0, l2 and H are lowered again and sever the next following element from the strip in the manner above described, produce the recess 4 and projection 5 between the holes I l and l I" and cut out a further hole H in a rearward portion of the strip 9.

The die I3 is provided with a cavity l8 into which the punch l2 presses the material of the strip for forming the projection 5. Immediately at the rear of the cavity l8 the die is formed with a projecting part I9 having a rearwardly extending inclined face 20. This projecting part l9 penetrates into the hole H of the strip during the punching operation and forms by means of its face 2| an abutment for the relatively weak transverse portion 22 in the strip between the formed as a result of the pressure exerted by the punch l2.

Figs. 5 to 8 represent a punching tool used in producing the described fastener element. This tool is formed of a lower die carrier 23 and of an upper punch carrier 24. The part 24 comprises a supporting plate 25 and a cover plate 26. The supporting plate carries two cylindrical guide bolts 21 and two further cylindrical guide bolts 28 which latter'- are provided with an annular groove 29. The plate 25 further carries the cutting punch l4 and a supporting bolt 30 in which the punches l0 and 12 are removably inserted.

The lower portion 23 of the punching tool also comprises a supporting plate 3| and a cover plate 32. These plates are provided with holes 33 and 33 traversing both plates and adapted to receive the guide bolts 21 and 28 of the upper tool portion 24. A die piece 34 is forced into theplate 3i and provided with an opening 35 extending through the entire height of the part 23 and the upper edge of which cooperates with the punch 14 for severing a fastener element from the strip 9.. The severed element can fall down the opening 35 to be carried away from the punching tool. A sleeve 36 inserted into the die piece 34 carries the die [3 cooperating with the punch l2 and is provided with an opening extending through the entire member 23. The upper edge of this opening cooperates with the punch Ill for punching out the holes ll, H, H" from the strip 9. The cut out material can fall through the opening 31 and be removed from the punching tool.

Sleeves 3B are inserted into the holes 33 of the die carrier 23 and are provided with a flange 3 9 at their ends projecting above the top face of the plate 3|. Clamping jaws 40 are pivotally mounted on each of these two sleeves 38 between the flange 39 and the top face of the plate 3|. Each clamping jaw is provided with an extenpunches and to secure clean punching edges and sion 4| situated in proximity of one of the holes 33' and having a lateral edge 42 formed as an arc of a circle tlfe radius of which corresponds to the radius of the holes 33. In a certain angular positionof the jaw 49, as represented in Fig. 5, the curved edge 42 is exactly in line with the edge of the hole 33'. The two opposed edges 43 of the jaws 40 cooperate with one another to I form a guide channel between themselves for guiding the strip 9 which is advanced by the rollers l1 and moreover laterally guided between rollers 44 which are rotatably carried by bolt 45 inserted into the plate 3|. When the two parts 23 and 24 of the punching tool are situated in operating position the guide bolts 21 and 28 penetrateinto the corresponding holes 33 and 33 Of the part 23. As represented in Fig. '7, theannular groove 29 of the bolt 28 is then situated on the level of the extension 4| of the clamping jaws 40. The annular groove is limited on its upper side by a conical or inclined surface 45 which is arranged to cooperate with the circular arc-shaped edge 42 of the extension. "4| of the clamping jaw.,

When during the punching operation the punch carrier 24 is urged towards the die carrier 23,

the guide bolts 28 penetrate further into the holes 33' and the inclined surface of each bolt acts against the corresponding edge 42 to push the extension 4| of the jaw 40 .towards the left in Fig. '7. Accordingly both clamping jaws 49 surfaces and according exactly punched contours of the fastener elements. The sleeve 38 inserted in the supporting plate 3| and carrying the dies slightly projects above the upper surface of'the supporting plate 3| so that an empty space is formed between the strip. 9 and the surface of the plate 3| allowing discharge of the air from the nozzle 52.

Fig. 9 shows a strip 53 from which fastener elements of the type represented in Figs. 1 and 2 are punched out, but in this case the elements are cut out in inversed position relatively to Fig". 3 with respect to the direction of feeding of the strip. The punch" which is used to sever an element from the end of the strip along the line 54 is positioned in such manner that exteriorly of the line 54, the jaw end portions 3 of the severed element are formed, while interiorly of the line 54 the head portion of the element to be severed with the next following punching operation is formed.

It is obviously possible to use a strip of mate- I rial of such a width thatsimultaneously two or are pivoted about the axis of the holes 33 towards each other and the curved edge 42 is maintained by the cylindrical surface of the bolt 28 above the groove 29 in the position in which it is in line with the edge of the hole 33. In the position of the clamping jaws 40 corresponding to the position in which the edges 42 are maintained by the cylindrical surface of the bolts 28 the edges 43-of .the jaws 40 are applied laterally against the strip 9 and maintain the strip immobile while the three punches Ill, l2 and I4 effect the punching operations. When the'punch carrier 24 is again raised or'moved away from the die carrier 23, the bolts 28 are moving outwardly in the holes 33' into the position represented in Fig. 7, so that the groove 29 arrives again on the level of the extension 4| of the clamping jaws 40 and both jaws are released, the edges 42 being no more maintained by the cylindrical surface of the bolts 28, but are'free to penetrate into the grooves 29, as represented in' dash and dot lines in Fig. 5. The edges 43 of the jaws release the strip 9 and this latter can now be advanced through one step by the feed rollers l1, until the free end of the strip, from which a fastener element has been severed during the punching operation abuts against the abutment surface l5 which is provided on a' piece 48 secured by means of a screw" to the supportingplate 3| of the die carrier 23.; The

opposed edges 43 of the clamping jawsJll are suitably cut out at 49 to allow free passage of the punches l9 and I2.

The,cover plate 32 of the die carrier 23 is more fastener elements according to Figs. 1 and 2 can be cut out side by side after each advancing step of the' strip, without producing any supplementary waste of -material, since adjacent elements would have a common cutting line along the outer edges of the jaw portions 2 and 3. The width of the strip in this case would be equal to the sum of the width of the finished fastener elements punched out side by side from the strip.

In the example according to Fig. 10 fastener elements 55 having V-shaped diverging jaws are punched out from a strip 55 in such position that the head portion 55 of one element is partly engaged between the jaw ends 58 of another element.

It is known to use aluminium or aluminium alloys for the production of fastener elements provided with a duct 50 connected to a passage,v

of separable fasteners, and to color such elements by previously subjecting them to anodic oxidation in an electrolytic bath. For this purpose the finished fastener elements are placed in rows on electrically conducting rods, and these rods carrying the elements are then used as electrodes. When making fastener elements according to described process, in which the elements are cut out from a strip corresponding in width to the width of the finished elements so that the lateral edges of the element are formed by the lateral edges of the strip, the process of oxidation and coloring can be simplified because the strip itself, before punching out the elements, can be oxidised and colored by electrolytic treatment. The outer lateral edges of the punching operation. By oxidising and coloring of the strip of material before punching out the elements much time and expense is saved by avoiding the necessity of placing the elements onthe electrode rods and the difficulty of producing a good electrical connection between the elements and the rods. Although I have shown and described particular embodiments of my improved method and means for producing slide fastener elements, I

do not desire the invention to be limited to the particular steps and arrangements disclosed, and I intend in the appended claims to cover all mod.

4 mesa-94s iiications which do not depart from the spirit and scope of my invention.

I claim:

1. The method of forming aislide fastener element having at one end spaced opposed tape gripping jaws and at the opposite end an inter-v locking head provided with a recess inone face and a corresponding projection at the opposite.

face, which comprises advancing. a strip step by step a distance less than the length of a. fastener element; and, after each step, effecting a single I tener elements are to be subsequently succes sively severed from the end of the strip, and (b) sever .a completed fastener element from the end of the strip along lines of severance which intersect a like aperture pierced at the end of a prior step and form a remaining part of the lateral edges'of the head of a fastener element including opposite lateral edges of such head,

and also form a complementary remaining part of the inner opposite opposedv lateral edges of the jaws of another fastener element, whereby such head is severed from such jaws in complementary overlapping relation therewith with the head embraced by the jaws; the shape of said aperture and the contour of said lines of severance being such as to space said inner opposite opposed lateral edges of the jaws the distance desired in the completed fastener element; and prior to so severing the fastener element from the end of the strip forming therein the recess and interlocking projection thereof so that a complete fastener element will be severed.

2. The method according to claim v1 in which the recess and corresponding projections of the fastener elements are as units successively formed, by the same single punching operations as perform the other operations on the strip.

3. The method according to claim 1 in which the completed fastener element is severed from the end of the strip along lines of severance which form the remaining part of the lateral edges of the head of the fastener element so severed, and also form the remaining part of'the inner opposite opposed lateraledses of the jaws of the fastener element to be severed from the strip at theend of the next successive step of advance of the strip.

4. The method according to claim 1 in which the completed fastener element is severed fromremaining part of the'lateral edges of the head of the fastener element to be severed from the strip at the end of the-next successive step of advance of the strip.

5. The method according to claim 1 in which the same single punching operation as performs the other operations on the strip also forms the recess and corresponding projection of the head of the fastener element to be severed from the strip at the end of the next successive step of.

advance of the strip. p

6. The method according to. claim 1 in which the same single punching operation as performs the other operations on the'strip also forms, adjacent an aperture pierced at the end of a prior step, the recess and corresponding projection of a fastener element, and there is entered I into such aperture an abutment for preventing deformation of that wall of said aperture which is adjacent said recess and projection.

' 7. The method according to claim 1 in which:

the width of the strip selected is that of the compieted fastener element, the lines of severance of the fastener elements from the strip inter-. secting the edges of the latter, so that said edges form the outer lateral edges of the completed fastener element.

8. The method according to claim 1 in which the strip selected is wide enough to permit theforming therefrom by the successive punching operations of at least two contacting rows of fastener elements, each punching operation severing from the end of the strip a fastener element from the end of each row along lines of severance which separate from each other the several fastener elements. so severed from the' end of the strip.

9 The. method according to claim 1 in which the strip selected is wide enough to permit the forming therefrom by the successive punching operations of at least two contacting rows of fastener elements having outer sides which con--' verge toward the fastener head, with the heads.

of the'fastener elements of one row facing in the opposite direction from those'of the other row, a side of each fastener element of each row contacting with a side of the opposite fastener element of the other row, and the inner lateraledge of a Jaw of each fastener element of each. row at the end portion of that jaw contactingwith the lateral edge of the head of-an adjacent fastener element of the same rowin overlapping relation therewith, with the end of such jaw contacting with the jaw end of thefastener sic-- ment-of-the other row oppositethe fastener element having such head, each punchinl operation severing from the end of the strip a faI-z tener element from the.,end of each. row along lines of severance which separate from each other the end'of th trip along lines 1 ev r ie 60. the several fastener elements so severed fromwhich form the remaining part of the inner opposite opposed lateral edges of the jaws of the fastener element so severed and also form the the end of the strip.

TINWINTERHALTER. 

